Mobile positioning via a mixture of GPS, cell towers, and previously mapped RF transmitters, e.g., Wi-Fi access points, is commonly available. However, indoor environments tend to be poor for GPS reception, necessitating reliance on other mechanisms. For example, one mechanism for improving reception is to make use of cell towers, e.g., using information about signal intensity from multiple known cell towers to triangulate an approximate location. Another approach is to use a database of known Wi-Fi transmitters, or other unregulated radio frequency (RF) transmitters.